Tag Archives: variability

Assessment of Chemical Composition, Variability, Heritability and Genetic Advance in Tetrapluera Tetraptera Fruits (Published)

Fruits of six genotypes of Tetrapluera tetraptera collected from six States in Southern Nigeria were analyzed for proximate, minerals, vitamins and phytochemical composition. The aims were to determine nutrient composition as well as variations among them, estimate the proportions of heritable and non heritable components, and expected genetic advance. The determinants were replicated 3 times in completely randomized design. Analysis of variance showed that proximate, minerals, vitamins and phytochemical were significant (P< 0.01). The results showed that the fruit is a good source of essential nutrients, minerals (potassium, iron, and calcium), vitamins A, B-complex; C and E. Heritable variations among the genotypes were observed in their ether, protein, crude fibre, potassium and Vitamin A contents. Selection based on these traits could lead to improvement of nutritional and phytochemical composition of T. tetraptera fruits, for more availability and consumption by average Nigerians.

Keywords: Chemical composition., Genetic Advance, Heritability, Tetrapluera Tetraptera Fruits, variability


The monthly mean maximum and minimum temperature data were analysed with the aim of revealing spatial and temporal pattern of long-term trends in the variables. The study is based on the data collected from Nigeria Meteorological Agency’s network of meteorological stations spread across Nigeria spanning from 1950-2012. A total of 20 meteorological stations spread across Nigeria were used for the analysis. Statistical techniques such as time-series plots, correlation analysis, descriptive statistics and Mann-Kendall’s test were used for the analysis. These analyses were executed using the R programming language, MATLAB and SPSS computer software packages. The results show latitudinal dependence of basic temperature characteristics with the northern part of the country exhibiting higher temperature variability than the south. The Mann-Kendall tests indicate that 17 stations (representing 85%) show significant increasing trends in the minimum temperature at the 0.01 level of significance while 16 stations (representing 80%) show significant increasing trends in the maximum temperature at the 0.01 and 0.05 significance levels. Port Harcourt and Ikeja have greatest trend coefficients among the 20 stations. The minimum temperatures have higher trend coefficients than the maximum temperatures for almost all the stations. The interstation spatial coherence revealed by correlation coefficients indicates that almost all the station’s minimum and maximum temperatures are positively correlated with others at the 0.01 level of significance. The Mann-Kendall’s test results show a general warming trend across the stations.

Keywords: Mann-Kendall, Nigeria, Trends, maximum temperature, minimum temperature, variability